The invention relates to a bearing arrangement for at least one camshaft and to a camshaft.
Camshafts are used to control the valves of an internal combustion engine. Typically a camshaft is provided in each case for the intake and exhaust valves, the camshaft being supported in an engine block. The support is achieved by way of bearing bridges, for example, which comprise bearing points for the shaft of the camshaft and in which rolling bearings are introduced. Depending on the design, the bearing bridges are split or in one piece. Non-split bearing bridges are generally associated with problems regarding the axial fixation of the rolling bearings. These generally comprise a rolling element cage, the rolling elements themselves, and an outer sleeve (also referred to as outer ring). In particular the outer raceways of the rolling elements are also located on the outer sleeve.
It is the object of the invention to provide a bearing arrangement for a camshaft that allows the axial fixation of a rolling bearing in a non-split bearing frame.
The invention achieves the object by providing at least one bearing frame, which includes at least one bearing point for accommodating a camshaft, by providing at least one rolling element cage, by providing at least one outer sleeve, and by designing and matching the bearing frame, the rolling element cage and the outer sleeve to each other in such a way that the outer sleeve has a smaller outside diameter than the inside diameter of the bearing point, and the rolling element cage has a smaller outside diameter than the inside diameter of the outer sleeve. The bearing frame is preferably not split. The rolling elements disposed in the rolling element cage can be balls or needles, for example. In one embodiment, two bearings points for accommodating a respective camshaft are provided in the bearing frame.
According to one embodiment, the outer sleeve has a radially outwardly extending edge at one end. The outer sleeve, which is seated inside the rolling element cage, has a radial edge or collar in this embodiment.
According to one embodiment, the rolling element cage has a clip-like structure at one end. The rolling element cage thus comprises a kind of clip or spring shackle at one end, a securing function being exercised by way of this clip or spring shackle.
One embodiment includes that the rolling element cage and the outer sleeve are designed and matched to each other in such a way that the end of the rolling element cage having the clip-like structure extends axially beyond the end of the outer sleeve having the radially outwardly extending edge. One end of the rolling element cage thus projects over the outer sleeve. This affects in particular the clip-like structures, resulting in a blocking function that prevents the rolling element cage from being pulled out of the outer sleeve.
One embodiment includes that the clip-like structure allows a movement of the rolling element cage in an axial direction and prevents it in the opposite direction. The structure allows in particular the rolling element cage to be introduced into the outer sleeve and prevents the reverse process of pulling out the same.
One embodiment includes that the rolling element cage has a radially outwardly extending edge at one end. In this embodiment, the rolling element cage likewise has an edge or a collar.
The invention further relates to a camshaft having at least one bearing arrangement according to at least one of the above embodiments. The camshaft is in particular a composite camshaft, which is to say the individual functional elements, such as the lobes, are manufactured separately and then applied to the shaft as the carrier element.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.